Quick Start

Go from zero to your first nutrition analysis in under a minute. Send natural language ingredients, get back structured nutrient data, diet labels, and confidence scores.

1. Get your API key

Sign up at nutrientapi.com to get a free API key. The free tier includes 100 recipes per month — no credit card required.

Your API key will look something like this:

sk_live_7a3b9f2e...

2. Make your first request

The API has a single endpoint: POST /v1/analyze. Send a recipe title, a list of ingredients in plain English, and the number of servings.

curl https://api.nutrientapi.com/v1/analyze \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "title": "Chicken and Rice Bowl",
    "ingredients": [
      "200g chicken breast",
      "1 cup brown rice",
      "1 tbsp olive oil",
      "2 cups steamed broccoli"
    ],
    "servings": 2
  }'

That's it. The API parses each ingredient, matches it to a USDA food, converts the portion to grams, calculates 14 nutrients, and classifies the recipe with diet and health labels.

3. Understand the response

A successful response includes four main sections:

• ingredients — per-ingredient breakdown with parsed quantities, matched USDA food, gram weights, confidence scores, and nutrients
• totals — summed nutrients across all ingredients for the full recipe
• per_serving — nutrients divided by the serving count
• diet_labels and health_labels — automatic classifications like "high-protein", "gluten-free", etc.

Here is an abbreviated response:

{
  "status": "success",
  "ingredients": [
    {
      "text": "200g chicken breast",
      "parsed": {
        "qty": 200,
        "unit": "g",
        "food": "Chicken breast, raw",
        "gram_weight": 200.0
      },
      "confidence": {
        "match": 0.97,
        "conversion": 1.0,
        "overall": 0.97
      },
      "nutrients": {
        "calories": 330.0,
        "protein": 62.0,
        "fat_total": 7.2,
        "carbs_total": 0.0
        // ... 14 nutrients total
      }
    }
    // ... remaining ingredients
  ],
  "totals": {
    "calories": 857.0,
    "protein": 76.4,
    "fat_total": 24.2,
    "carbs_total": 73.6
    // ...
  },
  "per_serving": {
    "calories": 428.5,
    "protein": 38.2,
    "fat_total": 12.1,
    "carbs_total": 36.8
    // ...
  },
  "diet_labels": ["high-protein"],
  "health_labels": ["dairy-free", "gluten-free"]
}

4. Code examples

Python

import requests

response = requests.post(
    "https://api.nutrientapi.com/v1/analyze",
    headers={
        "Authorization": "Bearer YOUR_API_KEY",
        "Content-Type": "application/json",
    },
    json={
        "title": "Overnight Oats",
        "ingredients": [
            "1/2 cup rolled oats",
            "1 cup whole milk",
            "1 tbsp honey",
            "1/4 cup blueberries",
        ],
        "servings": 1,
    },
)

data = response.json()

# Per-serving nutrients
print(f"Calories: {data['per_serving']['calories']} kcal")
print(f"Protein:  {data['per_serving']['protein']} g")
print(f"Carbs:    {data['per_serving']['carbs_total']} g")
print(f"Fat:      {data['per_serving']['fat_total']} g")

# Labels
print(f"Diet:   {data['diet_labels']}")
print(f"Health: {data['health_labels']}")

# Check confidence for each ingredient
for ing in data["ingredients"]:
    score = ing["confidence"]["overall"]
    if score < 0.8:
        print(f"Low confidence for: {ing['text']} ({score})")

JavaScript (Node.js)

const response = await fetch("https://api.nutrientapi.com/v1/analyze", {
  method: "POST",
  headers: {
    "Authorization": "Bearer YOUR_API_KEY",
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    title: "Overnight Oats",
    ingredients: [
      "1/2 cup rolled oats",
      "1 cup whole milk",
      "1 tbsp honey",
      "1/4 cup blueberries",
    ],
    servings: 1,
  }),
});

const data = await response.json();

// Per-serving nutrients
console.log(`Calories: ${data.per_serving.calories} kcal`);
console.log(`Protein:  ${data.per_serving.protein} g`);

// Flag low-confidence ingredients for review
data.ingredients
  .filter(ing => ing.confidence.overall < 0.8)
  .forEach(ing => {
    console.warn(`Review: ${ing.text} (confidence: ${ing.confidence.overall})`);
  });

Ruby

require "net/http"
require "json"
require "uri"

uri = URI("https://api.nutrientapi.com/v1/analyze")
http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = true

request = Net::HTTP::Post.new(uri)
request["Authorization"] = "Bearer YOUR_API_KEY"
request["Content-Type"] = "application/json"
request.body = {
  title: "Overnight Oats",
  ingredients: [
    "1/2 cup rolled oats",
    "1 cup whole milk",
    "1 tbsp honey",
    "1/4 cup blueberries",
  ],
  servings: 1,
}.to_json

response = http.request(request)
data = JSON.parse(response.body)

# Per-serving nutrients
puts "Calories: #{data['per_serving']['calories']} kcal"
puts "Protein:  #{data['per_serving']['protein']} g"

# Check for low confidence
data["ingredients"].each do |ing|
  if ing["confidence"]["overall"] < 0.8
    puts "Review: #{ing['text']} (#{ing['confidence']['overall']})"
  end
end

Next steps

• API Reference — full request/response schema, all 14 nutrients, error codes, and rate limits
• Confidence Scores — understand match and conversion confidence to build reliable applications
• Labels — how diet and health label classification works